Defroster



June 6, 1961 A. s. LEvlN 2,987,601

DEFROSTER Original Filed July ll, 1957 2 Sheets-Sheet 1 Il i) /1` lid H [/6 j@ 2 1N VENTOR.

A. S. LEVIN June 6, 1961 DEFROSTER 2 Sheets-Sheet 2 Original Filed July ll, 1957 W. mf w T N m mi T M. u A

United StatesPatent 2,987,601 DEFROSTER Abraham S. Levin, Philadelphia, Pa., assignor to Glenco Refrigeration Co., Philadelphia, Pa., a corporation of Pennsylvania Substituted for abandoned application Ser. No. 671,160, July 11, 1957. This application Aug. 19, 1959, Ser.

1 Claim. (Cl. 2.19-19) This application is a substitute of applicants application, Serial No. 671,160, tiled July 11, 1957, and which became abandoned.

My invention relates to a defrosting mechanism for refrigerators with particular application to refrigerators used in industrial establishments as distinguished from the relatively small domestic refrigerators.

`Commercial refrigerators are relatively large and .have two doors with a mullion which coacts with the back wall to support the refrigerating unit and against which the doors abut when in closed position.

Refrigerators of this type must be defrosted from time to time and, because they hold a relatively large quantity of deep-frozen foods, it is necessary that the evaporator be defrosted quickly to prevent appreciable rise in the temperature of the stored foods.

To this end, it has been proposed to use electrical heaters which are located in close association with the evaporator and which are energized when it is desired to defrost the evaporator. The electrical heaters referred to wear out and need servicing, or replacement and all such defrosters of which I am aware, have been so constructed and arranged that the task of removing, servicing and replacing the defroster is complicated, expensive and time consuming. This made it impractical, if not impossible to service the defrosting heaters on the job and without considerable dismantling of the associated parts.

One object of this invention is to produce an improved defrosting system composed of a number of separate elements, any one of which can be installed and removed as a unit with minimum time, skill and eiort.

A further object of the invention is to produce an irnproved defrosting system which can be applied to standard commercial refrigerators without any material alteration and without increasing their bulk and without interfering with any of the other parts.

A still further object is to produce an improved, inexpensive defrosting heater.

The full nature of the invention will be understood from the following specication and the accompanying drawings in which:

FIG. 1 is a perspective view of a commercial refrigerator, certain parts being broken away to show internal construction.

FIG. 2 is a horizontal sectional view looking in the direction of line 2 2 on FIG. l, certain parts being omitted.

FIG. 3 is a fragmentary perspective view of the defrosting heater embodying my invention.

FIG. 4 is a fragmentary vertical sectional view on line 4-4 on FIG. 2.

FIG. 5 is an enlarged horizontal sectional view looking in the direction of line 5-5 of FIG. 4.

FIG. 6 is an enlarged fragmentary vertical sectional View looking in the direction of line 6 6 on FIG. 4.

FIG. 7 is an elevational view of the front tube sheet of the evaporator showing the manner in which it is adapted for use in connection with my invention.

The refrigerator illustrated includes a cabinet formed of insulated rear wall 10, side walls 10 and 12 and two doors 14 and 16. In the lower right hand corner of the ICC refrigerator there is a machinery compartment for housing a conventional compressor-condenser unit which is not shown, and which is suitably connected to a conventional evaporator 20 in the usual manner. A blower 22 is preferably associated with the evaporator for circulating the cooled air by the evaporator. The refrigerator cabinet also includa a mullion 24, the upper portion of which coacts with the rear wall of the refrigerator to support the evaporator. The structure thus far described forms no part of the present invention.

In order to defrost the evaporator, I provide a heating system which includes a number of separate tubes 26, each of which encloses a conventional resistance element which terminate in binding posts 28 which are energized by wires 30. Tubes 26 pass through openings 32 in front tube sheet 34 which also has openings 35 for accommodating the tubes 36 of the evaporator coil. It will be understood that the other ends of the heater tubes and of the evaporator coil tubes pass through similar openings in tube sheet 40. In order detachably to secure the heater tubes in position, I provide plugs 44, which are best shown in FIG. 5 and which are preferably formed of rubber, or the like. Plugs 44 are provided with holes through which binding posts 28 of the heater tubes 26 pass. By this arrangement, any heater tube can be removed by merely pulling out its corresponding plug 44 without disturbing any of the other tubes. The wires 30 which energize the heaters in tubes 26 are suitably connected, in an individually separable manner to a source of current such as electric outlet 46.

When tubes 26 of FIG. 3 are inserted in position through tube sheets 34 and 40, they will be located in. intimate association with the tubes 36 of the evaporator so that, when the heaters in these tubes are energized, they will defrost the evaporator coils very rapidly. Should one of tubes 26, or the resistance element therein, become defective, it can be easily pulled out and replaced on the spot, and without disturbing any other parts, and without pulling the refrigerator out of action for any appreciable tlme.

In order to dispose of the water produced by the defrosting of the evaporator coils, I provided a trough 48 having a drain opening 50 and to insure that this opening 5t) will be open to permit passage of the water, I provide an auxiliary heater tube 52 which is constructed and mounted in the same manner as tubes 26. Because the trough is spaced from the evaporator coil, it does not get as cold and, therefore, it will be defrosted, and drain opening 50 will be opened before any appreciable amount of Water reaches trough 48.

From the foregoing, it will be seen that my improved defrosting system is inexpensive to make, that its component units may be installed, or removed separately, that this can be done With any of its other parts, that the entire assembly is mounted in the already existing mullion, and that the installation or removal, of any unit can be carried out on the spot and with minimum tools, efforts, skill and time.

What I claim is:

In a refrigerator of the type which includes a mullion, a tube sheet parallel to, and spaced inwardly from, said mullion, spaced evaporator coils carried by, and extending substantially normal to said tube sheet, a defroster for defrosting said coils, said defroster including spaced heater tubes, carried by, and projecting substantially normal to, said mounting, there being openings in said mullion and in said tube sheet registering with the spaces between said evaporator coils and through which said heater tubes are adapted to pass into the spaces between said coils, and means for nergizing and de-energizing 2,487,6774

said heater tubes. 2,529,215

References Cited in the le of this patent 2859945 UNITED STATES PATENTS 2,238,378 Summerfield Apr. 15, 1941 533,705

4 Rott Nov. 8, 1949 Hieke Nov. 7, 1950 Kleist Nov. 11, 1958 FOREIGN PATENTS Canada Nov. 27, 1956 

